Receiving system



Aug. 10, 1926. I 1,595,729

A. PRESS RECEIVING SYSTEM Filed June 17 1920 I I 4 WITNESSES: Pore/ma 1. 0R

' flbraham Pram I BY 73 ATTORNEY Patented Aug. 10, 1926.

UNITED STATES PATENT OFFICE."

ABRAHAM PRESS,YOIF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

RECEIVING SYSTEM.

- Application filed June 17, 1920. Serial No. 389,538.

This invention relates to wireless triodes and more especially to those in which a grid is maintained more positive with respect to both a co-operating filament and a plate. One of the more important objects of my invention is to increase the detector sensitivity of such a device.

I have discovered that, by substantially balancing the accelerating potential of the filament-grid circuit by a retarding potential, the detectors sensitivity is materially increased for an incoming signal. This increased sensitivity, as a feature of my invention, is obtained by destroying the balance established between the accelerating and retarding potentials above described by introducing the voltage setup by the incoming signal into either one of the two opposing circuits. Thus, I have found, in particular, although a grid current is continually maintained between the filament and the grid, yet, for a given potential between the grid and plate, no current will flow through the telephones intercalated in the latter circuit, except for such values of the grid-filament potential as counterbalance the potential betweenthe grid and the plate. As a further feature of my invention, therefore, I provide such an arrangement of circuits whereby the values of the plate current only exist for a given grid-to-plate difference of potential, after a predetermined value of the grid-filamentpotential has been reached.

In the prior art, it will be found that, for ordinary variations of the grid potential,

. a current, whether less or more, is always found to exist in the plate circuit. The above indicated property of a sudden springing into being of the plate current is especially valuable, since the detector sensitivity of the triode depends upon the curvature of the plate-current grid-voltage characteristic.

Other objects and features of the invention will naturally follow from an inspection of the drawings, when taken in conjunction with the accompanying description. Such features will also be made a part of the claims.

Figure l is a diagram representing one embodiment of my invention.

'Figure 2 is a diagram representing an alternative form, wherein the incoming signal is impressed upon the grid-plate circuit.

Figure 3 is a diagram conformable to the showing of Fig. 1 except for the introduction of potentiometer devices for producing the voltage controls.

Figure 4 is a chart illustrating the relationship of the plate current to the variable grid potential or various plate-grid voltages.

A vacuum tube 1, of the usual type, is provided with three electrodes, viz: the filament 2, the grid 3 and the plate 4, to form a triode. Preferably, the grid is of the usual fine-mesh variety. It is usual to excite the filament by means of an adjustable battery arrangement 5 in order to pro vide a stream of current-carrying particles from the filament to the grid. An adjustable battery 6 is provided between the grid and the filament in such manner that the grid constitutes the positive pole of the above battery unit. Similarly, a second adjustable battery 7 is connected between the grid and the plate in such manner that the plate 4 constitutes the negative pole of such adjustable battery 7. In one form of my device, as in Fig. 1, I intercalate a telephone 8, or other equivalent indicating device, in the connections leading from the plate 4 to the battery 7. Thus, under the above circumstances, I include also a coupling coil 9 between the filament 2 and the battery unit 6. The'coupling coil 9 may be ofany desired type but I have shown it associated with an antenna 10 by means of an antenna-coupling-coil member 11.

In Fig. 2, the relative positions of the telephone 8 and the coupling coils 9 and 11 are shown as interchanged.

In Fig. 3, the arangement, for the most part, is similar to that in Fig. 1, but, in order to provide more delicate adjustment vracy of adjustment.

of the voltages between the filament-to-grid and grid-to-plate, potentiometers 12 and 13' are indicated having adjustable connections 14 and 15 for obtaining the required dellcondenser 16 together with a series couipling-coil member 9, has manifest advantages in those cases where tuning or resonance reinforcements are contemplated. The condenser 17 is similarly connected across the terminals of the telephone 8.

In Fig. 4, I have plotted the plate current of atriode against the accelerating potentialof the battery 6 in the grid-filament circuit, while maintaining a constant retard ing potential of the battery 7 in the gridplate circuit. A number of curves are drawn, for various values of the retarding potential, as indicated, in order to determine the relative potential adjustments necessary to obtain the steepest slope of the plate-current accelerating-potential characteristic at the points of substantially zero current.

In the operation of my invention, I contemplate balancing the filament-to-grid voltage against the grid-to-plate voltage. Ideally, under these circumstances, no current would then flow between the filament and the plate. On the other hand, current will undoubtedly flow'between the filament andthe'grid. I have found, however, that there isa critical grid-to-plate-voltage adjustment, see, for example, the ll-volt curve of Fig. l, which gives the steepest rise in plate current for a given increment in the grid-to-filament voltage. Such type of adjustment, as a feature of my invention, thus becomes an important matter, especially from the standpoint of a detector arrangement.

NVhile I have described and illustrated several embodiments of my invention, it will be apparent to those skilled in the art' that various changes, modifications, substitutions, additions and omissions may be made in the apparatus without departing from the spirit and scope of the invention.

I claim as my invention:

*1. A method of receiving signals with a triode valve having anintermediate grid electrode positive with respect to a plate and a cathode, comprising the steps of so balancing the opposing potentials of the grid-plate and grid-filament circuits that.

substantially zero plate-current is obtained and then subjecting such balanced triode to the influence of the signals.

2. The combination with a triode valve havin a cathode an anode and an interu u 7 n o mediately disposed rld, of means for givin 'the TlCl a ositive )otential with respect t3 a l i to the cathode. and means for )roducin Preferably, I provide said filament and plate.

a substantially balancing potential between the grid and anode.

3. In combination with a tube having a W filament, a fine-mesh grid, and a plate;

means for passing an electron current be-.

tween filament and grid, and potential-producing means for n-eutralizmg the'electron current flow between grid and plate.

4. In combination with a vacuum-tube electrodes, a third electrode adjacent one of said electrodes of said pair, further means for substantially balancing out an electron flow between said third electrode and said adjacent electrode, and additional means for disturbing said balance. j

'6. A detector comprising the filament,

grid and plate of a trio'devalve, means connesting said filamentand grid for passing a current toward sald grid, further means connecting said grid and plate for substantially balancing out any current flowing'intosaid plate, and wave-influencing means and an indicating means in the connections between 7. The combination with an electron tube having a cathode, an anode and anvinterniedia tely'disposed grid, of means for giving the grid a positive potential with respect to the cathode, further means for producing a substantially balancing potential between the grid and anode, and still further means for disturbing said balance. V

S. In combination with an electron tube having afilam'ent,"a plate and an intermediately disposed grid, means for giving the grid a positive potential with respect to the filament, further means for producing a substantially balancing potential between the gridand plate, still further means for disturbing said balance, and additional meansfor indicating said disturbance of the balance.

9. The combination with a triode valve having a filament, a grid and a plate, of 'means for producing a normally constant grid-filament voltage, a source of signal current for temporarily increasing saidgridfilament'voltage, and means for causing the plate current to be' existent only after a pre determined increased value of the grid-filaine nt' voltage has been reached.

10. In a method of operating an electron tube having substantially normally constant accelerating andretarding gridfilament and grid-plate potentials respectively, the steps of varying one ofsai'dfpotentials inaccordance with a signal and so adjusting the normally constant potentials as to obtain a maximum ascent characteristic of the plate current with respect to said varied poten- 11. In combination with a triode valve, a plurality of circuit means for making the intermediate electrode positive with respect to the remaining triode, and a capacity coupling vfor said plurality of circuit means.

12. In combination with a triodevalve, a plurality of circuit means for making the intermediate electrode positive with respect to V the remaining two electrodes of said triode, and furthermeans for providing a resonance coupling for said plurality of circuit means. 7

l3. The combination with an'electron tube having a filament, a grid and a plate. of a grid-plate circuit including a source of electromotive force, a grid-filament circuit including a source of electromotive force sub stantially opposi-ngsaid first mentioned electromotive force, said grid being more positive than the filament and plate, and a coupling between the two circuits. I 1 14,-. The combination with an electron tube having a filament, agrid and a plate, of a: grid-plate circuit including a source of electromotive force, a grid-filament circuit including 'a source of 'electromotive force substantially opposing said first-mentioned electromotive'force, said grid being more positivethan the said filament and plate, a coupling between the-two circuits, an antenna and ground electrically associated with said coupling and a detecting device in oneof said circuits 15. The combination with an electron tube having a cathode, a grid and a plate, of a grid-plate circuit, a grid-cathode circuit, means for rendering said grid positive with respect to both plateand cathode, a source of signal impluses individual to one of said circuits and a translating device individual to the other of said circuits.

16. The combination with an electron tube vhaving a cathode, a 7 grid and aplate, of a grid-plate circuit, a grid-cathode circuit, means for rendering said respectto both plate and cathode, a source of signal impulses individual to said gridcathode circuit, and a translating device individual to said grid-plate circuit.

17. Thecombination with an electron tube having acathode, a grid and a plate, oft

a grid-plate circuit,ra grid-cathode circuit,

means for rendering said grid positive with respect to both plate and cathode, a source of signal impulses individual to one of said circuits, a translating device individualetothe other of said circuits, and a feedback ;co,upling;device between the two circuits.

two electrodes of said grid positive with 18. The combination with an electron tube having a cathode, a grid and a plate, of a grid-plate circuit, a grid-cathode circuit, means for rendering said grid positive with respect to both plate and cathode, a source of signal impluses individual to said gridcathode circuit, a translating device individual to said grid-plate circuit, and 'a-ieed-back coupling device between the two circuitsj; -1

19. The combination with an electron tubehaving a cathode, a grid and a plate, of agrid-plate circuit, a grid-cathode cir-. cuit, means for rendering said grid positivewith respect to both plate and cathodmand a coupling device between the two circuits,

20. The combination. with an electron tube having a cathode, a grid and a plate, of a grid-plate circuit, agrid-cathode circuit, means for rendering said grid positive with respect to both plate and cathode, a source of signal impulsesindividual to one of said circuits, and means for so adjusting the relative potentials that the current in said grid-plate, periods may be reduced to a negligibly small value. a

21. The combination with :an'= electron tube having a cathode, a grid and a plate, of a grid-plate circuit, a gridscathodecircuit, means for rendering said gridpositive with respect to' bothplate of signal impulses in said cuit, and means torso adju ting the relative potentials that the current in said grid pl ate circuit during non-signalling periods may be reduced to a negligibly small Valuer 22. The combination with an electron tube having a cathode, a grid and a plate, of a grid-plate circuit, a grid-cathode circuit, means for rendering said grid positive with respect to both plate and. cathode, at least one of said circuits containing a translating device for signal currents, and means for so adjusting the relative potentials that the current in said grid-plate circuit during non-signalling'periods may be reduced to a negligibly small value.

The combination with an electron tube having a cathode, a grid and a plate, of a grid-plate circuit, a grid-cathode circuit, means for rendering said grid positive with respect to both "plate and cathode, a source of signal impulses individual to one of said circuits, a coupling device between the twoclrcuits, and means for so adjusting the relative potentials that the current in said grid-plate circuit during hon-signaL ling periods may be reduced to a negligibly small value.

24. The combination with an electron tube having a cathode, a grid and a plate, of a grid-plate circuit, a grid-cathode circuit, means for rendering said grid positive with respect. to both plate and cathode, a' source of signal impulses in .said grid-cathode cirand cathode, a sourcegrid-cathode circircuit during non-signalling .respect to both plate and cathode, a source cuit, a coupling device between the two cir cuits, and means for so adjusting the relative potentials that the current in said gridplate circuit during non-signalling periods may lee-reduced to a negligibly small value. 25. The combination with an electron tube having a cathode, a grid and a. plate, of a grid-plate circuit, a grid-cathode circuit,.mean for rendering said grid positive with'respect to both plate and cathode, at least one of said circuitscontaining a translating device for signal currents, a coupling device between thetwo circuits, and means for so adjusting the relative potentials that the current in said grid-plate circuit during non-signalling periods may be reduced to a negligibly small value. 7

26. The combination with an electron tube having a cathode, a grid and a plate, of a grid-plate circuit and a grid-cathode circuit forming also a plate-cathode circuit, means for rendering said grid positive with of signal impulses included in said platemeans for rendering said grid positive with- *respect to both plate and cathode, a source plate circuit during non-signalling tube having a cathode,

cathode circuit, and. means for utilizing signal currents also included in said platecathode circuit.

27. The combination with an electron a grid and a plate, of a grid-plate circuit and a grid-cathode circuit forming also a plate-cathode circuit,

of signal impulses included in said platecathode circuit, means for utilizing signal currents also included in said plate-cathode circuit, and feed-back coupling means between said grid-plate and grid-cathode circuits,

9.8. The combinationwith an electron tube having a cathode, a grid and a plate, of a grid-plate circuit anda grid-cathode circuit forming also a plate-cathode circuit, means for rendering said grid positive with respect to both plate and cathode, a source of signal impulses included in said platecathode circuit, means for utilizing signal currents also included in said plate-cathode circuit, and means for so adjusting the relative potentials that the current in said gridperiods may be reduced to a negligibly small value.

29. The combination with an electron tube having a cathode,,a grid and a plate,- of a grid-plate circuit and a grid-catlibdecircuit forming also a plate-cathode circuit, means for rendering said grid positive with respect to both plate and cathode, a source of signal impulses included in said plate-cathode circuit, means for utilizing signal currents also included in said plate-cathode circuit, feedbackcoupling means between said grid-plate :and' grid-cathode circuits, and means for so adjusting the relative potentials that the current in said grid-plate circuit durin non-signalling periods may be reduced to a-neglig'ibly small value. V

r 30. In a method of operating. an electron tube having, substantially V normally constant accelerating and retarding grid-filament and.

grid-platepotentials, the steps of varying one of said potentials in accordance with a signal and so adjusting the normallyron stant potentials as to obtain substantially no plate current during non-signalling periods and to obtain a maximum ascent characteristic of the plate current with-re'spctflto said varied potential. 31. In a method of operating a signaling system including an electron tube. having a. cathode, an anode and an intermediately diss posed grid, together with grid-anode'circuits including sources of ac: celerating and retarding potentials, respectively, the steps of causing saidpo-tentialsto be so adjusted, at times, that substantially no plate current is obtained, and causing said adjustment tobe di turbedv in accords ancewith a signal. i V

32. In a method. of operating a signaling grid-cathode and system including an electron tube having a i cathode, an anode'and an intermediately-disposed grid, together with coupled; gridcathode and grid-anode circuits including sources of accelerating. and. retarding potentials, respectively,the steps. of causing said potentials to be so-adjusted', at times, that substantially no plate current is obtained, causing the potential in one of said circuits to-be altered. in accordance with a signal, and utilizing the resultant: current variations in the other circuit. Y

33. In a signaling system,- the combination with an electron tube having a cathode, an anode and an intermediately disposed. grid, of grid-cathode and grid-anode'circuits' including sources of accelerating and retard.- ing potentials, respectively, and means for causing oneo-f said potentials to be varied in accordance with asignal.

34.. In a signaling system, the combination with an-electrontube having a cathode,'an anode and an intermediately disposed grid, of coupled grid-cathode and grid-anode cir cuits including sources of accelerating and retarding potentials, respectively, means for causing the potential inone of said circuits to be altered in accordance with-a signal, and means for utilizing the resultant current variations in the other circuit.

85. In a signaling-systennthe combination with an electron tube having a cathode, an anode and an intermediately disposed grid, of means including sources" of accelerating and retarding potentials for causing substantially zero anode-current to be obtained, at times, means for causing one otsaid potentials to be varied in accordance with, a signal.

with an electron tube having a cathode, an one of said circuits to be altered in accordanode and an intermediately disposed grid, ance With a signal, and means for utilizing 1 of coupled grid-cathode and grid-anode cirthe resultant current variations in the other cuits, means comprising sources of accelercircuit.

ating and retarding potentials included in In testimony whereof, I have hereunto said circuits, respectively, for causing subsubscribed my name this 12th day of June, stantially zero anode-current to be obtained, 1920.

at times, means for causing the potential in ABRAHAM PRESS. 

